1. Field of the Invention
The present invention relates generally to an apparatus for magnetically recording information to and/or reproducing information from a recording medium, and more particularly, to a Digital Audio Tape Recorder, or DAT.
2. Description of the Related Art
One type of apparatus for magnetically recording information to and/or reproducing information from a recording medium, such apparatus hereinafter referred to as a magnetic recording/reproduction apparatus, is a Digital Audio Tape recorder, or DAT.
A conventional DAT 1 is shown in FIG. 1. As shown in the drawing, the DAT 1 mainly comprises a chassis 2, on top of which are provided a variety of mechanisms and components, including a tape cassette loading and ejecting mechanism 3, a reel drive mechanism 4, a rotary cylinder 5 and a tape loading mechanism 6.
The tape cassette loading and ejecting mechanism 3, hereinafter referred to as simply the tape cassette loading mechanism 3, loads a tape cassette (not shown in the diagrams) to a predetermined position within the DAT 1. The tape cassette loading and ejecting mechanism 3 mainly comprises a cassette holder 7 into which the tape cassette is loaded, a slider cam assembly 8 capable of sliding in the X1-X2 direction as indicated in the diagram, and a drive mechanism which, however, is not shown in the diagram. It should be noted that the cassette holder 7, the chassis 2 and the slider cam assembly 8 are made of metal.
The cassette holder 7 and the slider cam assembly 8 are connected by a metal shaft 9 such that as the slider cam assembly 8 moves the cassette holder 7 moves with it.
The movement of the cassette holder 7 is determined by a cam groove 11a of a cam 11 formed on the slider cam assembly 8 together with a substantially L-shaped guide groove 13 formed in a resinous side wall of the chassis. In other words, the drive mechanism causes the slider cam assembly 8 to move in the X1 direction as shown in FIG. 1, which causes the cassette holder 7 to first move horizontally in the X1 direction and then drop downward. By so doing, a tape cassette loaded in the cassette holder 7 is transported to the above-described predetermined position within the apparatus 1 for recording/reproduction. It should be noted that the cam 11 is made of a resinous material to facilitate the sliding of the shaft 9 along the cam 11.
The reel drive mechanism 4 rotatably drives a supply reel and a take-up reel, neither of which is shown in the drawing. Additionally, the magnetic tape (not shown) extracted from the tape cassette is wound around the rotary cylinder 5 at a predetermined angle, with magnetic recording of information to and reproduction of information from the magnetic tape performed as the tape moves. It should be noted that the rotary cylinder 5 is mounted atop a resinous drum base 14. Additionally, the tape loading mechanism 6 extracts the magnetic tape from the tape cassette and winds the magnetic tape around the rotary cylinder 5 at a predetermined angle.
The mode switching mechanism 10 comprises a mode switching gear, a link and a mode switching plate, none of which is shown in the drawing. The mode switching gear is rotatably driven by a mode switching motor 15. It should be noted that reference number 19 in FIG. 1 indicates a motor bracket. Additionally, a circuit board 16 that controls the mode switching motor 15 is provided adjacent to the mode switching motor 15. Additionally, the tape cassette loading mechanism 3 and the tape loading mechanism 6 are connected to the mode switching plate, with the mode switching motor 15 moving the mode switching plate to a plurality of predetermined mode switching positions, thereby accomplishing the mode switching of the apparatus 1.
It should be noted that reference number 21 represents an amplifier assembly comprising an amplifier that amplifies the recording signal and a wiring board that sends the amplified signal to the rotary cylinder 5.
However, the conventional apparatus 1 having the structure described above has a drawback, in that when the tape cassette is loaded to the cassette holder 7 a static electric charge on the tape cassette is transferred to the cassette holder 7. As noted previously, the cam 11 of the slider cam assembly 8 that engages the metal shaft that connects the cassette holder 7 and the slider cam assembly 8 is made of a resinous material in order to facilitate the sliding of the shaft 9 therealong. Moreover, the arm 18 that moves the slider cam assembly 9 is also coated with a resinous material for the same purpose. As a result, the static electricity is not discharged externally via the slider cam assembly 8 but instead remains on the cassette holder 7. The presence of this static electric charge can cause the integrated circuits mounted on the above-described adjacent circuit board to be reset or otherwise operate in a mistaken manner.
At the same time, the conventional apparatus 1 as described above has an additional drawback in that, in the process of loading the tape cassette into the cassette holder 7 and moving the slider cam assembly 8 to a predetermined position directly above the amplifier assembly 21, the slider cam assembly 8 becomes an antenna for radiating electromagnetic waves generated from the wiring board, which can adversely affect the operation of the other electronic components within the apparatus 1. As a result, conventionally the amplifier assembly 21 is covered with a shield casing not shown in the diagram. However, providing such a shield casing requires the use of valuable space in an apparatus having a dense concentration of electronic components, and is therefore undesirable.
Accordingly, it is a general object of the present invention to provide an improved and useful magnetic recording/reproduction apparatus in which the drawbacks described above are eliminated.
More specifically, a first object of the present invention is to provide an improved and useful magnetic recording/reproduction apparatus in which a static electric charge on the cassette holder is discharged externally and eliminated with the loading of the tape cassette into the cassette holder.
In addition, a second object of the present invention is to provide a magnetic recording/reproduction apparatus in which the slider cam assembly is prevented from acting as an antenna for the radiation of electromagnetic waves generated from the amplifier assembly.
The above-described objects of the present invention are achieved by a magnetic recording/reproduction apparatus for magnetically recording information to and/or reproducing information from a recording medium, the magnetic recording/reproduction apparatus having an electrically grounded tape cassette loading/ejecting mechanism, the tape cassette loading/ejecting mechanism comprising:
a chassis adapted to be electrically grounded;
a cassette holder for loading a tape cassette into and/or ejecting a tape cassette from the apparatus;
a slider cam assembly mounted on the chassis and mechanically coupled to the cassette holder for moving the cassette holder to and from a predetermined loading position inside the apparatus; and
a static electric charge removal mechanism electrically connected to the cassette holder for removing a static electric charge from the cassette holder.
According to this aspect of the invention, because the cassette holder is electrically grounded by the ground terminal the static electricity is discharged externally and eliminated not via the chassis when a static electric charge on the tape cassette is transferred to the cassette holder when the tape cassette is loaded into the cassette holder, thus avoiding damage to or interference with the circuit board due to the presence of a static electric charge.
Additionally, the above-described objects of the present invention are also achieved by a magnetic recording/reproduction apparatus for magnetically recording information to and/or reproducing information from a recording medium, the magnetic recording/reproduction apparatus having an electrically grounded tape cassette loading/ejecting mechanism, the tape cassette loading/ejecting mechanism comprising:
a chassis adapted to be electrically grounded mounting an electronic component that generates electromagnetic waves;
a cassette holder for loading a tape cassette into and/or ejecting a tape cassette from the apparatus;
a slider cam assembly mounted on the chassis and mechanically coupled to the cassette holder for moving the cassette holder to and from a predetermined loading position inside the apparatus; and
an electromagnetic wave removal mechanism, the electromagnetic wave removal mechanism contacting the slider cam assembly at least when the slider cam assembly has moved the cassette holder to the predetermined loading position inside the apparatus so as to electrically ground the slider cam assembly and cassette holder.
According to this aspect of the invention, when the slider cam assembly has moved to a point directly above the amplifier unit and is exposed to electromagnetic waves generated by the amplifier unit, the slider cam assembly is electrically grounded and thus functions not as an antenna but as a shield casing covering the electronic components, eliminating the adverse effects of noise interference on these electronic components.
Additionally, the above-described objects of the present invention are also achieved by the magnetic recording/reproduction apparatus as described above, wherein the flexible member of the electromagnetic wave removal mechanism has a substantially comb-like shape.
According to this aspect of the invention, each of the individual teeth of the comb-like flexible member flex so as to envelopingly contact the slider cam assembly and thus ground the slider cam assembly securely at multiple points. Additionally, because the slider cam assembly and each of the teeth of the comb-like flexible member form a ground contact, the effectiveness of the ground can be increased by increasing the number of teeth in the comb-like flexible member.